Bitmap转成byte[]再用base64转成string

用户上传头像，上传的头像图片需要上传至服务器的MySQL数据库保存，当用户上传成功之后每次登陆后从数据库获取头像信息显示。

由于之前一直使用JSON作为客户端和服务器端数据传输形式，JSON虽然使用方便但是不支持自定义类型，所以遇到的问题就是将二进制图片文件转成String,再传到服务器并保存到数据库。

在查阅了一些资料后想出了一个方法：

1，将图片转换成Byte[]

2，利用Base64将Byte[]加密编码转换成String

3，利用JSON将String传到服务器，由于图片一般转换后的String 是很大的，所以在mysql中保存为MEDIUMTEXT类型。方便以后从数据库直接读出来通过JSON再返回客户端解析后显示。

4，显示时将从数据库读出来的String通过Base64解码成Byte[];

5，用BitmapFactory将Byte[]转换成Bitmap显示。

A客户端向服务器端发送：

[java] view plain copy

print?

1. private void edit_headPicture(Bitmap bitmap) {  
2.         ByteArrayOutputStream baos = new ByteArrayOutputStream();//将Bitmap转成Byte[]  
3.         bitmap.compress(Bitmap.CompressFormat.PNG, 50, baos);//压缩  
4.         headPicture =Base64.encodeToString(baos.toByteArray(),Base64.DEFAULT);//加密转换成String  
5.         int n=headPicture.length();  
6.         Thread submit=new Thread(new SubmitThread());  
7.         submit.start();  
8.     }  
9.       
10.     class SubmitThread implements Runnable  
11.     {  
12.         Message msg = handler.obtainMessage();  
13.         @Override  
14.         public void run() {  
15.             // TODO Auto-generated method stub  
16.             JSONObject object=new JSONObject();  
17.             try {  
18.                 object.put("headPicture", headPicture);  
19.                 msg.what=Server(object);  
20.                 handler.sendMessage(msg);  
21.             } catch (JSONException e) {  
22.                 // TODO Auto-generated catch block  
23.                 e.printStackTrace();  
24.             }  
25.         }  
26.     }  
27.     public int Server(JSONObject object)  
28.     {  
29.         String path=LoginActivity.URL+"SetInfoManager";  
30.         try{  
31.             URL url=new URL(path);  
32.             String content = String.valueOf(object);  
33.             HttpURLConnection conn = (HttpURLConnection) url.openConnection();  
34.             conn.setConnectTimeout(5000);  
35.             conn.setDoOutput(true);  
36.             conn.setRequestMethod("POST");  
37.             conn.setRequestProperty("User-Agent", "Fiddler");  
38.             conn.setRequestProperty("Content-Type", "application/json");  
39.             OutputStream os = conn.getOutputStream();  
40.             os.write(content.getBytes());  
41.             os.close();  
42.             int code = conn.getResponseCode();  
43.             if(code == 200)  
44.             {  
45.                 BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));  
46.                 String result="";  
47.                 result = in.readLine();  
48.                 in.close();  
49.                 return Integer.parseInt(result);  
50.             }  
51.             else return 0;  
52.         }catch (MalformedURLException e) {    
53.             // TODO Auto-generated catch block    
54.             e.printStackTrace();    
55.         } catch (IOException e) {    
56.             // TODO Auto-generated catch block    
57.             e.printStackTrace();    
58.        }   
59.         return 0;  
60.     }  

private void edit_headPicture(Bitmap bitmap) {ByteArrayOutputStream baos = new ByteArrayOutputStream();//将Bitmap转成Byte[]bitmap.compress(Bitmap.CompressFormat.PNG, 50, baos);//压缩headPicture =Base64.encodeToString(baos.toByteArray(),Base64.DEFAULT);//加密转换成Stringint n=headPicture.length();Thread submit=new Thread(new SubmitThread());submit.start();}class SubmitThread implements Runnable    {    Message msg = handler.obtainMessage();@Overridepublic void run() {// TODO Auto-generated method stubJSONObject object=new JSONObject();try {object.put("headPicture", headPicture);msg.what=Server(object);handler.sendMessage(msg);} catch (JSONException e) {// TODO Auto-generated catch blocke.printStackTrace();}}    }    public int Server(JSONObject object)    {    String path=LoginActivity.URL+"SetInfoManager";    try{    URL url=new URL(path);    String content = String.valueOf(object);        HttpURLConnection conn = (HttpURLConnection) url.openConnection();        conn.setConnectTimeout(5000);        conn.setDoOutput(true);        conn.setRequestMethod("POST");        conn.setRequestProperty("User-Agent", "Fiddler");        conn.setRequestProperty("Content-Type", "application/json");        OutputStream os = conn.getOutputStream();        os.write(content.getBytes());        os.close();        int code = conn.getResponseCode();        if(code == 200)        {        BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));        String result="";        result = in.readLine();        in.close();        return Integer.parseInt(result);        }        else return 0;    }catch (MalformedURLException e) {              // TODO Auto-generated catch block              e.printStackTrace();          } catch (IOException e) {              // TODO Auto-generated catch block              e.printStackTrace();         }     return 0;    }

B:服务器接收代码：

[java] view plain copy

print?

1. protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  
2.         StringBuffer buffer=new StringBuffer();  
3.         String line="";  
4.         request.setCharacterEncoding("UTF-8");  
5.         BufferedReader reader=request.getReader();  
6.         while((line=reader.readLine())!=null)  
7.         {  
8.             buffer.append(line);  
9.         }  
10.         try {  
11.             JSONObject object=new JSONObject(buffer.toString());  
12.             int result=new SetInfoManagerDB(object).Update();  
13.             response.getOutputStream().write((result+"").getBytes());  
14.         } catch (JSONException e) {  
15.             // TODO Auto-generated catch block  
16.             e.printStackTrace();  
17.         }  
18.     }  
19.   
20.   
21. <span style="white-space:pre">        </span> sql="update companyview set headPicture=? where e_Name=?";  
22.             try {  
23.                 try {  
24.                     stmt=conn.prepareStatement(sql);  
25.                     stmt.setString(1, object.getString("headPicture"));  
26.                     stmt.setString(2, username);  
27.                     stmt.executeUpdate();  
28.                     stmt.close();  
29.                     return 4;  
30.                 } catch (SQLException e) {  
31.                     // TODO Auto-generated catch block  
32.                     e.printStackTrace();  
33.                     return 6;  
34.                 }  

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {StringBuffer buffer=new StringBuffer();String line="";request.setCharacterEncoding("UTF-8");BufferedReader reader=request.getReader();while((line=reader.readLine())!=null){buffer.append(line);}try {JSONObject object=new JSONObject(buffer.toString());int result=new SetInfoManagerDB(object).Update();response.getOutputStream().write((result+"").getBytes());} catch (JSONException e) {// TODO Auto-generated catch blocke.printStackTrace();}}<span style="white-space:pre"></span> sql="update companyview set headPicture=? where e_Name=?";try {try {stmt=conn.prepareStatement(sql);stmt.setString(1, object.getString("headPicture"));stmt.setString(2, username);stmt.executeUpdate();stmt.close();return 4;} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();return 6;}

C:客户端解析并显示：

[java] view plain copy

print?

1. String s=view.getString("headPicture");  
2.                     if(s.equals(""))  
3.                         btn_user.setImageResource(R.drawable.ic_launcher);  
4.                     else  
5.                     {  
6.                         byte[] bytes = Base64.decode(view.getString("headPicture"), Base64.DEFAULT);  
7.                         btn_user.setImageBitmap(BitmapFactory.decodeByteArray(bytes, 0, bytes.length));  
8.                     }